Microwave Spectra of Methylcyclopropanes. I. 2,2-Difluoro-1-Methylcyclopropane

Abstract

The microwave spectrum of 2,2‐difluoro‐1‐methylcyclopropane was observed in the range 8‐38 gHz. The ground and first excited methyl torsional states were assigned, and a barrier of 2260 ± 150 cal/mole was obtained from the splittings in the first excited torsional state. The dipole moment was measured and found to be μ A = 2.03 ± 0.03 D , μ B = 1.19 ± 0.04 D , μ C = 0.31 ± 0.07 D , and μ total = 2.37 ± 0.05 D . The barrier to internal rotation in this molecule is compared to barriers in similar molecules.